In this book, occurrence, distribution, hydrogeochemistry of arsenic in groundwater and feasibility of raw laterite (RL) and/or treated laterite (TL) as arsenic adsorbent are discussed in detail. Raw laterite samples collected from various locations were subjected to different treatment methods to enhance the adsorbent performance for arsenic removal from contaminated groundwater in continuous fixed-bed mode operation.
Chapter 1 gives an overview of the state of current research in this area, while Chapter 2 details the hydrogeochemistry of arsenic contaminated water. Chapter 3 focuses on various technologies involved and used for the removal of arsenic. The application of RL as arsenic adsorbent from water medium is discussed in Chapter 4. The results of adsorption in batch mode is presented under different operating conditions such as pH of solution, adsorbent dose, contact time, arsenic concentration, temperature, and speed of agitation. The adsorption kinetics in stirred tank vessel is predicted by applying shrinking core model. The model is also applied to contaminated groundwater (CGW)/ RL system. The chapter gives an account of the continuous fixed-bed column performances of RL bed.
In Chapter 5, the acid activation on RL in the context of characteristics changes and arsenic adsorption behaviour is discussed. Both batch and column mode adsorption of arsenic using acid-activated laterite is investigated under different operating conditions. In Chapter 6, the results of acid–base TL are presented as arsenic adsorbent for CGW. A design of household column filter using TL bed is also proposed to remove arsenic from CGW.
1. Arsenic in Groundwater and its Health Effects
2. Hydrogeochemistry of Arsenic-contaminated Water
3. Arsenic Removal Processes and Advantages of the Adsorption Process
4. Application of Raw Laterite as an Arsenic Adsorbent
5. Application of Acid-treated Laterite as an Arsenic Adsorbent
6. Application of Acid–Base Treated Laterite as an Arsenic Adsorbent
7. Conclusions and Future Work